The World is a very complex system. It is easy to have too simple a view of it, and it is easy to do harm and to make things worse under the impulse to do good and make things better.

Are we to regard the world of nature simply as a storehouse to be robbed for the immediate benefit of man? ... Does man have any responsibility for the preservation of a decent balance in nature, for the preservation of rare species, or even for the indefinite continuance of his race?

It is much more accurate to identify the factors of production as know-how (that is genetic information structure), energy, and materials, for, as we have seen, all processes of production involve the direction of energy by some know-how structure toward the selection, transportation, and transformation of materials into the product

It is clear that the building of models is not a purely mechanical process but requires skill of a high order - not merely mathematical skill but a sensitivity to the relative importance of different factors and a critical, almost an artistic, faculty in the selection of behaviour equations which are reasonable, tentative hypotheses in explaining the behaviour of actual economies.

The human experience can almost be summed up in the observation that, whereas all decisions are of the past, all decisions are about the future. The image of the future, therefore, is the key to all choice-oriented behavior. The character and quality of the images of the future which prevail in a society is therefore the most important clue to its overall dynamics.

The ability to work with systems of general equilibrium is perhaps one of the most important skills of the economist - a skill which he shares with many other scientists, but in which he has perhaps a certain comparative advantage.

Without the heroic, man has no meaning; without the economic, he has no sense. Economic man is most likely to be economic woman - a good wife, pulling the coat tails of her heroic husband, checking his extravagances of speech and action with words of caution and good sense. But without the heroic coat tails to pull, life for both of them would be dull and savorless indeed.